Using NI 488.2 Receive routine returns a empty string

[master9991]

Hi All
Why do I get a empty string when I am stepping through the code using the "Receive" routine (NI 488.2).
But I do get a return string if I do not step through the code.
BTW I am using visual basic version 6 / Windows XP OS.

Sample code:
    Dim idnStr        As String * 20
    Dim iBoardID   As Integer
    Dim iDUTAddr  As Integer

    iBoardID = 0
    iDUTAddr = 5

    'Write *IDN? to the instrument
    Call Send(iBoardID, iDUTAddr, "*IDN?", DABend)
   
    'Read String from instrument
    Call Receive(iBoardID, iDUTAddr, idnStr, DABend)

[RayFarmer]

Hi,

Maybe you are receiving a timeout error but because you are not receiving the return value you maybe missing it.

The default timeout is 10 secs.

Regards

Ray Farmer

[gpibtester]

Hi,

In your Receive statement, it is currently setup like so:

Call Receive(iBoardID, iDUTAddr, idnStr, DABend)

where it is using the termination of DABend. However, the DABend termination is for the Send call. For terminating the Receive call, try using STOPend instead, as shown below:

Call Receive(iBoardID, iDUTAddr, idnStr, STOPend)

According to the online help for Receive, the Termination STOPend stops the read when a byte is received with the EOI line asserted.

Hope this information helps!

gpibtester